Fiber conveying device for an open-end spinning apparatus

ABSTRACT

An improved fiber conveying device for an open-end spinning apparatus in which textile fibers are adapted to be introduced from a feed point in clusters of discrete fibers into an electrostatic field which transports the fibers to a spinning device where they are twisted into yarn.

Uted States Patent Amato et al. Nov. 20, 1973 [54] FIBER CONVEYING DEVKCE FOR AN 3,176,351 4/1965 Keen 57/38.3 X OPEN-END SPINNING APPARATUS 2 233 232 Z I em Inventors: Richard Ammo, Bolton, Mass; 3,665,695 5/1972 Amato 57/58.9l Leo L. Chabot, Cumberland, R]. 3,670,486 6/1972 Murray 57/58.89

[73] Assignee: Electrospin Corporation, Columbus,

h Primary ExaminerJ0hn Petrakes [22] Filed Aug 26 1971 Attorney-Anthony D. Cennamo et al.

[21] Appl. No.: 175,049

[57] ABSTRACT U.S. Cl. 57/58.95, 57/91, 57/156 An improved fiber conveying device for an open end spinning apparatus in which textile fibers are adapted [58] meld of Search 'g f to be introduced from a feed point in clusters of discrete fibers into an electrostatic field which transports References Cited the fibers to a spinning device where they are twisted into arn. UNITED STATES PATENTS y 3,105,349 10/1963 Palm et a1 57 91 x 5 Claims, 2 Drawing Figures FIBER CONVEYING DEVICE FOR AN OPEN-END SPINNING APPARATUS BACKGROUND OF THE INVENTION The invention relates to an improved in open-end type spinning frames and more particularly to an apparatus amd method of conveying textile fibers and introducing them as discrete groups or clusters into an electrostatic field that is effective in transporting and assembling each successive cluster on a yarn tail which, with the cooperation of a continuously rotating spinning device, twists the assembled fibers into yarn.

In known electrostatic spinning devices, such as that shown in U.S. Pat. No. 3,411,284, issued NOv. 19, 1968 to A. Corbaz et a]. for Method and Apparatus for Spinning Textile Fibers, the electrostatic field extends across an air gap between a drafting system that mechanically advances the fibers into the field and a spinning head for twisting and spinning the fibers to form yarn. The fibers are supplied to the drafting system in the form of roving or sliver and are discharged from the drafting system as a stream of discrete fibers into the electrostatic field. The field is effective to align the fibers and define a flow path which the fibers follow to the spinning head.

Such drafting systems usually include a pair of driven inlet drafting rollers between which roving'or sliver is fed. A pair of drivenintermediate belts entrained about driven rollers and so-called nose bars and intermediate idler rollers are caused to advance fibers therebetween to a pair of fiber discharge drafting rollers.

With this sort of drafting system, the fibers enter the electrostatic field as a stream of discrete fibers. According to the spinning head utilized with the present invention, a yarn tail extends from said head into the electrostatic field and is adapted to receive the flow of fibers. for advancement through said spinning head which twists them into yarn.

The spinning head utilized with the fiber conveying device of the present invention forms the subject matter of a separate US. Pat. application, Ser. No. 135,320, filed Apr. 19, 1971 and entitled Spinning Head, now U. S. Pat. No. 3,706,193, and assigned to the same assignee as this application.

This spinning head includes a rotatable spindle with a so-called gripper carried thereby. The yarn tail referred to above extends upwardly from the gripper through the fiber inlet end of the spindle into the electrostatic field and during rotation of the spindle said gripper is effective in twisting and spinning the fibers into yarn which is drawn downwardly through the exit end of said spindle.

With a continuous flow of fibers from the discharge drafting rollers to the point of their assembly to the yarn tail creates a problem of applying a negative twist by the gripper to the fibers intermediate said gripper and rollers. Such a condition is considered quite serious, for with long staple fibers, the discharge drafting rollers may have sufficient hold so as to apply a 100 percent twist to the fibers which, of course, would be cancelled as they advanced through the gripper and result in yarn of zero twist being drawn from the exit end of the spindle.

To prevent what is considered an excessive amount of negative twist upon the fibers in the area intermediate the gripper and discharge drafting rollers, the present invention provides a means for maintaining a physical separation between the fibers being assembled to the yarn tail and those being ejected from the discharge drafting rollers into the electrostatic field or so-called transport zone.

SUMMARY OF THE INVENTION The fiber conveying device of the present invention includes the usual inlet drafting rollers and intermediate rollers about which fiber advancing belts are entrained. The fiber discharge rollers which include a socalled cot roller and front roller are formed so as to eject the fibers into the electrostatic field or transport zone in the form of clusters or bunches. The ejection of these clusters or bunches of fibers is at a rapid and regular rate but with sufficient hasitation between ejections so as to maintain a hesitation separation between the fibers being assembled to the yarn tail and those being ejected by the discharge rollers. The cot roller and front roller are disposed in nipping relation and a portion of the outer peripheral surface of the front roller is machined to form a land which during rotation thereof permits only the unmachined peripheral surface of the front roller to make nipping contact with the cot roller.

During the performance of their intended function, the fiber discharge rollers are continuously rotating and are effective in intermittently ejecting clusters of fibers into the fiber transport zone. When the unmachined surface of the front roller is in nipping contact with the peripheral surface of the cot roller, a cluster of fibers is ejected and when this nipping contact between the rollers is lost, advancement of the fibers ceases until further rotation again brings these surfaces into contact.

It is a general object of the invention to provide a means for controlling the quantity of textile fibers that are delivered to an electrostatic spinning apparatus to form yarn.

It is a further object of the invention to present fibers to an electrostatic spinning apparatus in discrete groups or clusters so as to maintain a physical separation between the fibers being drawn into the spinning head to form yarn and their source of supply.

A more specific object of the invention is to provide an improved drafting system for an electrostatic spinning apparatus which will prevent excessive negative twisting of the fibers in the area intermediate their source of supply and the spinning head.

These and other objects of the invention will become apparent as further details are disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in greater detail by reference to a specific embodiment thereof as shown in the accompanying figures of drawings, wherein:

FIG. 1 is a perspective view and partially in section of a portion of an electrostatic spinning apparatus to which the device according to the invention is applicable, and

FIG. 2 is a sectional view in side elevation showing the drafting systems fiber discharge rollers and the configuration of the front roll and the manner of ejecting fibers in discrete clusters DESCRIPTION OF THE PREFERRED EMBODIMENT As the general construction and operation of an electrostatic type open-end spinning apparatus is known and familiar to those conversant in the art and as the invention is entirely concerned with an improved fiber conveying device applicable thereto, it is only considered necessary here to illustrate and describe those parts of such an apparatus directly concerned with a preferred form of the present invention.

Referring to FIG. 1, the spinning apparatus shown embodies a fiber drafting system generally identified by numeral and includes a pair of driven inlet drafting rollers 11 and 12 between which roving or sliver 13 is fed.

From the inlet drafting rollers 11 and 12, the sliver is advanced between a pair of drafting rollers 14 and 15 and then a similar pair of rollers depicted by numerals l6 and 17. As the sliver is advanced between the drafting rollers, the individual fibers become straightened, aligned and prepared for presentation to the means for spinning them into yarn as is well known to those familiar with the art.

The fibers after leaving the rollers 16 and 17 are advanced further through the drafting system by a pair of endless belts entrained about and driven by a pair of drive rollers 18 and 19. These belts are driven about a so-called nose bar and form a path of travel continuous with that provided by the preceding pairs of drafting rollers. In FIG. 1, the endless belt driven by roller 18 and its guiding nose bar are identified by numerals 20 and 21 respectively and the endless belt driven by roller 19 and its guiding nose bar are shown at 22 and 23.

Endless belts 20 and 22 direct the fibers being advanced therebetween to a pair of fiber discharge rollers 24 and 25. In this form of drafting system, roller 24 is commonly referred to as the cot roller and roller 25 as the front roller.

Below and spaced from the discharge rollers, a portion of a spinning head is shown at 26 along with its fiber inlet end 27 from which extends a so-called yarn tail 28.

The discharge rollers 24 and 25 are caused to rotate continuously during the performance of their intended function in the direction of the indicating arrows 29 and 30 respectively and, being in nipping relation, are effective in ejecting fibers into the electrostatic field which fills the gap between the spinning head 26 and said discharge rollers. This electrostatic field forms a flow path for the fibers and as they are ejected into said field, they are caused to move toward and assemble to the yarn tail 28 which is continuously being drawn into the spinning head that twists said fibers into yarn.

As shown in FIG. 2, roller 25 or the so-called front roller has a portion of its outer peripheral surface removed as by machining, forming a land 32 which is of lesser diameter than the unmachined peripheral surface thereof. During rotation of the discharge rollers, only the unmachined peripheral surface of the roller 25 makes nipping contact with the peripheral surface of roller 24 and is effective in ejecting clusters of fibers into the electrostatic field for assembly to the yarn tail 28.

To summarize the operation, textile fibers are fed into the drafting system in the form of roving or sliver which is advanced therethorugh by the plurality of pairs of drafting rollers and rotating endless belts or socalled aprons disposed adjacent the discharge rollers.

The discharge rollers are effective in ejecting clusters of discrete fibers into the electrostatic field which transports them to a position for assembly to a yarn tail extending into said field from the spinning head. By ejecting the fibers in the form of clusters from the discharge rollers, a physical separation between the fibers being assembled on the yarn tail and those being ejected from said discharge rollers is maintained. By providing this fiber separation, excessive negative twist of the fibers in this area is prevented thereby resulting in the desired amount of positive twist in the newly formed yarn as it is withdrawn from the exit end of the spinning head.

Although the present invention has been described in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.

We claim:

1. An improved open-end spinning process in which textile fibers are conveyed from a feed point through a transport zone to a fiber assembly point by means of an electrostatic field, said process comprising providing a supply of fibers for introduction into the electrostatic field, introducing separated discrete clusters of discrete fibers into the electrostatic field, assembling each successive cluster on a yarn tail located a predetermined distance from the point of entry of fibers into the electrostatic field and continuously twisting the assembled fibers into yarn.

2. A process as defined in claim 1 wherein the clusters are introduced into the electrostatic field at a rate such that no assembled fibers will extend from the assembly point on the yarn tail to the point of entry into the electrostatic field.

3. A process as defined in claim 1 wherein yarn is withdrawn from the twisting zone at a rate proportional to that at which clusters of fibers are introduced into the electrostatic field so that the location of the fiber assembly point within the field remains substantially constant.

4. An improved fiber conveying device for an openend spinning apparatus of the type in which discrete textile fibers are introduced into an electrostatic field and transported for assembly to a yarn tail extending into said field from a twisting device for continuously twisting the assembled fibers into yarn, said improved fiber conveying device comprising a plurality of pairs of juxtaposed drafting rollers for advancing the fibers therebetween and means for introducing separate discrete clusters of discrete fibers from said conveying device into said electrostatic field for transport by the latter to a point of assembly on said yarn tail.

5. The improved fiber conveying device according to claim 4 wherein said means for introducing discrete clusters of fibers into said electrostatic field comprises at least one of a pair of said drafting rollers having a land formed on the peripheral surface thereof whereby continuous advance of said fibers is interrupted by periodic and momentary loss of contact between the peripheral surfaces of the pair of said drafting rollers.

Dedication 3,772,868.-Ri0har0l A. Amato, Bolton, Mass. and Leo L. Ohabot, Cumberland,

RI. FIBER CONVEYING DEVICE FOR AN OPEN-END SPIN- NING APPARATUS. Patent dated Nov. 20, 1973. Dedication filed Mar. 23, 1977, by the assignee, Electrospz'n Oorpomtz'on. Hereby dedicates to the Public the entire term of said patent.

[Ofiicial Gazette May 10, 1,977.] 

1. An improved open-end spinning process in which texTile fibers are conveyed from a feed point through a transport zone to a fiber assembly point by means of an electrostatic field, said process comprising providing a supply of fibers for introduction into the electrostatic field, introducing separated discrete clusters of discrete fibers into the electrostatic field, assembling each successive cluster on a yarn tail located a predetermined distance from the point of entry of fibers into the electrostatic field and continuously twisting the assembled fibers into yarn.
 2. A process as defined in claim 1 wherein the clusters are introduced into the electrostatic field at a rate such that no assembled fibers will extend from the assembly point on the yarn tail to the point of entry into the electrostatic field.
 3. A process as defined in claim 1 wherein yarn is withdrawn from the twisting zone at a rate proportional to that at which clusters of fibers are introduced into the electrostatic field so that the location of the fiber assembly point within the field remains substantially constant.
 4. An improved fiber conveying device for an open-end spinning apparatus of the type in which discrete textile fibers are introduced into an electrostatic field and transported for assembly to a yarn tail extending into said field from a twisting device for continuously twisting the assembled fibers into yarn, said improved fiber conveying device comprising a plurality of pairs of juxtaposed drafting rollers for advancing the fibers therebetween and means for introducing separate discrete clusters of discrete fibers from said conveying device into said electrostatic field for transport by the latter to a point of assembly on said yarn tail.
 5. The improved fiber conveying device according to claim 4 wherein said means for introducing discrete clusters of fibers into said electrostatic field comprises at least one of a pair of said drafting rollers having a land formed on the peripheral surface thereof whereby continuous advance of said fibers is interrupted by periodic and momentary loss of contact between the peripheral surfaces of the pair of said drafting rollers. 